scholarly journals Uncertainty of perceptual tone onset and tone frequency

2020 ◽  
Vol 41 (1) ◽  
pp. 376-377
Author(s):  
Satoshi Okazaki ◽  
Minoru Tsuzaki
Keyword(s):  
1988 ◽  
Vol 59 (5) ◽  
pp. 1524-1539 ◽  
Author(s):  
D. P. Phillips

1. The responses of cat auditory cortex neurons are largely dominated by transient stimulus events, including tone-pulse onset. In addition, these neurons often receive sensitive inhibitory inputs in tone frequency-intensity domains flanking the excitatory one centered at characteristic frequency (CF). These observations suggest that auditory cortex neurons might be sensitive to the spectral splatter that occurs at tone onset due to the tone-pulse envelope shape. 2. To investigate this hypothesis, single neurons in the primary auditory cortex of anesthetized cats were studied for the form of their spike-rate versus tone-level functions using CF tone pulses of different rise times. Stimuli were presented to the contralateral ear using a calibrated, sealed stimulus delivery system. 3. Some neurons with monotonic rate-level functions for conventional (5-10 ms) rise-time tones were relatively insensitive to variations in tone-pulse rise time. Other monotonic neurons showed rate-level functions that became increasingly bell shaped for shorter rise-time stimuli. All neurons with bell-shaped, nonmonotonic rate-level functions for conventional rise-time tones became increasingly nonmonotonic for shorter rise-time signals. In the same neurons, lengthening of tone rise times typically reduced the slope of the high-intensity, descending limb of the rate-level function, in some cases to zero. 4. This pattern of rise-time effects is consistent with previous evidence on the association between rate-level function shape and the presence of inhibitory tone response areas flanking the excitatory one at CF. The present data suggest that cortical neurons are sensitive to the gross shape of the short-term stimulus spectrum at tone onset, and that for many neurons, the nonmonotonic form of CF tone rate level functions may be configured as much by the rate of tone onset as by the plateau amplitude of a tone pulse.


2011 ◽  
Vol 30 (4) ◽  
pp. 831-835
Author(s):  
Yu-chun Huang ◽  
Zai-lu Huang ◽  
Ben-xiong Huang ◽  
Shu-hua Xu

NeuroImage ◽  
2003 ◽  
Vol 18 (2) ◽  
pp. 448-459 ◽  
Author(s):  
Andrew C Papanicolaou ◽  
Eduardo Castillo ◽  
Joshua I Breier ◽  
Robert N Davis ◽  
Panagiotis G Simos ◽  
...  

2019 ◽  
Author(s):  
Jesyin Lai ◽  
Stephen V. David

ABSTRACTChronic vagus nerve stimulation (VNS) can facilitate learning of sensory and motor behaviors. VNS is believed to trigger release of neuromodulators, including norepinephrine and acetylcholine, which can mediate cortical plasticity associated with learning. Most previous work has studied effects of VNS over many days, and less is known about how acute VNS influences neural coding and behavior over the shorter term. To explore this question, we measured effects of VNS on learning of an auditory discrimination over 1-2 days. Ferrets implanted with cuff electrodes on the vagus nerve were trained by classical conditioning on a tone frequency-reward association. One tone was associated with reward while another tone, was not. The frequencies and reward associations of the tones were changed every two days, requiring learning of a new relationship. When the tones (both rewarded and non-rewarded) were paired with VNS, rates of learning increased on the first day following a change in reward association. To examine VNS effects on auditory coding, we recorded single- and multi-unit neural activity in primary auditory cortex (A1) of passively listening animals following brief periods of VNS (20 trials/session) paired with tones. Because afferent VNS induces changes in pupil size associated with fluctuations in neuromodulation, we also measured pupil during recordings. After pairing VNS with a neuron’s best-frequency (BF) tone, responses in a subpopulation of neurons were reduced. Pairing with an off-BF tone or performing VNS during the inter-trial interval had no effect on responses. We separated the change in A1 activity into two components, one that could be predicted by fluctuations in pupil and one that persisted after VNS and was not accounted for by pupil. The BF-specific reduction in neural responses remained, even after regressing out changes that could be explained by pupil. In addition, the size of VNS-mediated changes in pupil predicted the magnitude of persistent changes in the neural response. This interaction suggests that changes in neuromodulation associated with arousal gate the long-term effects of VNS on neural activity. Taken together, these results support a role for VNS in auditory learning and help establish VNS as a tool to facilitate neural plasticity.


1984 ◽  
Vol 41 (5) ◽  
pp. 506-508 ◽  
Author(s):  
D. B. Quine ◽  
D. Regan ◽  
K. I. Beverley ◽  
T. J. Murray

2016 ◽  
Vol 2016 ◽  
pp. 1-18 ◽  
Author(s):  
Patrice Voss ◽  
Maryse Thomas ◽  
You Chien Chou ◽  
José Miguel Cisneros-Franco ◽  
Lydia Ouellet ◽  
...  

We used the rat primary auditory cortex (A1) as a model to probe the effects of cholinergic enhancement on perceptual learning and auditory processing mechanisms in both young and old animals. Rats learned to perform a two-tone frequency discrimination task over the course of two weeks, combined with either the administration of a cholinesterase inhibitor or saline. We found that while both age groups learned the task more quickly through cholinergic enhancement, the young did so by improving target detection, whereas the old did so by inhibiting erroneous responses to nontarget stimuli. We also found that cholinergic enhancement led to marked functional and structural changes within A1 in both young and old rats. Importantly, we found that several functional changes observed in the old rats, particularly those relating to the processing and inhibition of nontargets, produced cortical processing features that resembled those of young untrained rats more so than those of older adult rats. Overall, these findings demonstrate that combining auditory training with neuromodulation of the cholinergic system can restore many of the auditory cortical functional deficits observed as a result of normal aging and add to the growing body of evidence demonstrating that many age-related perceptual and neuroplastic changes are reversible.


2013 ◽  
Vol 25 (12) ◽  
pp. 2047-2060 ◽  
Author(s):  
Yamit Cohen ◽  
Luba Daikhin ◽  
Merav Ahissar

What do we learn when we practice a simple perceptual task? Many studies have suggested that we learn to refine or better select the sensory representations of the task-relevant dimension. Here we show that learning is specific to the trained structural regularities. Specifically, when this structure is modified after training with a fixed temporal structure, performance regresses to pretraining levels, even when the trained stimuli and task are retained. This specificity raises key questions as to the importance of low-level sensory modifications in the learning process. We trained two groups of participants on a two-tone frequency discrimination task for several days. In one group, a fixed reference tone was consistently presented in the first interval (the second tone was higher or lower), and in the other group the same reference tone was consistently presented in the second interval. When following training, these temporal protocols were switched between groups, performance of both groups regressed to pretraining levels, and further training was needed to attain postlearning performance. ERP measures, taken before and after training, indicated that participants implicitly learned the temporal regularity of the protocol and formed an attentional template that matched the trained structure of information. These results are consistent with Reverse Hierarchy Theory, which posits that even the learning of simple perceptual tasks progresses in a top–down manner, hence can benefit from temporal regularities at the trial level, albeit at the potential cost that learning may be specific to these regularities.


1973 ◽  
Vol 59 (2) ◽  
pp. 415-424
Author(s):  
PER S. ENGER

1. The nervous activity of single auditory neurones in goldfish brain have been measured. 2. Four types of acoustic stimuli were used, (1) pure tones, (2) noise of one-third octave band width, (3) noise of one-octave band width with centre frequency equal to the pure tone, and (4) white noise. 3. Except for white noise, these stimuli produced the same response to equal sound pressures. The white noise response was less, presumably because the frequency range covered by a single neurone is far narrower than the range of white noise. 4. The conclusion has been reached that for low-frequency acoustic signals, the acoustic power over a frequency band of one to two octaves is integrated by the nervous system. 5. The masking effect of background noise on the acoustic threshold of single units to pure tones is strongest when the noise band has the same centre frequency as the test tone. In this case the tone threshold increases linearly with the background noise level. 6. When the noise band was centred at a different frequency from the tone, the masking effect decreased at a rate of 20-22 dB/octave for the first one-third octave for a tone frequency of 250 Hz. For a tone of 500 Hz the masking effect of lower frequencies was stronger and was reduced by only some 9 dB/octave for the first one-third octave.


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